Ch. 6 Warm-Up What are the 2 main types of cells? Which Domains do they consist of? List 3 ways that eukaryotes differ from prokaryotes.

Chapter 6 A Tour of the Cell

Three differences between prokaryotic and eukaryotic cells. You Must Know Three differences between prokaryotic and eukaryotic cells. The structure and function of organelles common to plant and animal cells. The structure and function of organelles found only in plant cells or only in animal cells.

2 Types of Cells: Prokaryotes: Domain Bacteria & Archaea Eukaryotes (Domain Eukarya): Protists, Fungi, Plants, Animals

A Prokaryotic Cell (bacteria)

Prokaryote Vs. Eukaryote “before” “kernel” No nucleus DNA in a nucleoid No organelles other than ribosomes Small size Primitive i.e. Bacteria & Archaea “true” “kernel” Has nucleus and nuclear envelope Membrane-bound organelles with specialized structure/function Much larger in size More complex i.e. plant/animal cell

Nucleus Function: control center of cell Contains DNA Surrounded by double membrane (nuclear envelope) Continuous with the rough ER Nucleolus: region where ribosomal subunits are formed

Nucleus Contains DNA Function: control center of cell Surrounded by double membrane (nuclear envelope) Continuous with the rough ER Nuclear pores: control what enters/leaves nucleus Chromatin: complex of DNA + proteins; makes up chromosomes Nucleolus: region where ribosomal subunits are formed

Ribosomes Function: protein synthesis Composed of rRNA + protein Types: Free ribosomes: float in cytosol, produce proteins used within cell Bound ribosomes: attached to ER, make proteins for export from cell

Endomembrane System: Regulates protein traffic & performs metabolic functions

Endoplasmic Reticulum (ER) Network of membranes and sacs Types: Rough ER: ribosomes on surface Function: package proteins for secretion, send transport vesicles to Golgi, make replacement membrane Smooth ER: no ribosomes on surface Function: synthesize lipids, metabolize carbs, detox drugs & poisons, store Ca2+

Endoplasmic Reticulum (ER)

Golgi Apparatus Function: synthesis & packaging of materials (small molecules) for transport (in vesicles); produce lysosomes

Lysosomes Function: intracellular digestion; recycle cell’s materials; programmed cell death (apoptosis) Contains hydrolytic enzymes

Vacuoles Function: storage of materials (food, water, minerals, pigments, poisons) Membrane-bound vesicles Eg. food vacuoles, contractile vacuoles Plants: large central vacuole -- stores water, ions

Parts of plant & animal cell p 108-109

Mitochondria Function: site of cellular respiration Double membrane: outer and inner membrane Cristae: folds of inner membrane; contains enzymes for ATP production; increased surface area to  ATP made

Chloroplasts Function: site of photosynthesis Double membrane Thylakoid disks in stacks (grana); stroma (fluid) Contains chlorophylls (pigments) for capturing sunlight energy

Peroxisomes Functions: break down fatty acids; detox alcohol Involves production of hydrogen peroxide (H2O2)

Cytoskeleton: network of protein fibers Function: support, motility, regulate biochemical activities

Plant Cells Cell wall: protect plant, maintain shape Composed of cellulose Plasmodesmata: channels between cells to allow passage of molecules

Plant Cells Only Animals Cells Only Central vacuoles Lysosomes Chloroplasts Centrioles Cell wall of cellulose Flagella, cilia Plasmodesmata Desmosomes, tight and gap junctions Extracellular matrix (ECM)

Endosymbiont theory Mitochondria & chloroplasts share similar origin Prokaryotic cells engulfed by ancestors of eukaryotic cells Evidence: Double-membrane structure Have own ribosomes & DNA Reproduce independently within cell